The present invention generally relates to paravanes and other underwater towed apparatus and more particularly to paravanes having wing sections with high lift-to-drag and high lift-to-weight ratios and provided with means for maintaining the paravanes at a predetermined ordered depth.
Generally, paravanes towed by minesweepers are connected to a cable system so that the paravanes are positioned behind and laterally offset from the tow point of the minesweeper to maximize the sweep area. Various depth control means have been utilized to maintain the paravanes at a predetermined depth. One type of depth control means utilizes a float device with a length of cable extending between the float and the paravane such that the operating depth of the paravane is controlled by changing the length of the cable. However, the cable length often limits the effective working depth, and the float and cable assembly tends to impose undesirable drag forces on the towing vessel. Another depth control means which overcomes some of the drawbacks with the abovementioned float controls utilizes a depth sensor which is coupled with a rudder or control flap, the movement of which causes the paravane to ascend or descend. However, some of these depth control means as utilized in conventional paravane construction have caused the paravane to oscillate excessively or "hunt" in the water in finding the equilibrium position at the desired working depth. Such oscillating action produces dynamic loads and undesirable stresses in the cable system.
Paravanes and other underwater apparatus which include various depth control means are generally exemplified by U.S. Pat. Nos. 2,709,981; 2,879,737; 2,981,220; 3,560,912; and 3,703,876.